Can you find out the remainder when 3^300 is divided by 5?

What is next number in the pattern below:

131 517 192 123 ?

Find the number of squares in the below-given picture.

A large water tank has two inlet pipes (a large one and a small one) and one outlet pipe. It takes 3 hours to fill the tank with the large inlet pipe. On the other hand, it takes 6 hours to fill the tank with the small inlet pipe. The outlet pipe allows the full tank to be emptied in 9 hours.

What fraction of the tank (initially empty) will be filled in 0.64 hours if all three pipes are in operation? Give your answer to two decimal places (e.g., 0.25, 0.5, or 0.75).

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?

What's a single-digit number with no value?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

If 21x = 79x, what is the value of x?